1. Field of the Invention
This invention relates to a method and means for mounting a wind turbine on the upper end of a supporting tower and more particularly to a method and means wherein the wind turbine is winched up the length of the tower on a carriage or sled which rolls along a pair of guide rails positioned on opposite sides of the tower.
2. Description of the Related Art
Wind turbines are becoming more popular in the production of electrical energy. The wind turbine assembly normally comprises a rotor-driven generator or turbine mounted atop a tower which may reach heights of 70 meters or more. The tower is normally first erected and the wind turbine is then mounted on the upper end of the tower by means of an extremely large crane. The customary method of mounting the wind turbine on the upper end of the tower is quite expensive in that the extremely large crane used for positioning the wind turbine on the upper end of the tower is very expensive and it is costly to have such a crane on site during the erection procedure. Thus, it is advantageous to be able to mount the wind turbine on the upper end of the tower without the use of the extremely large crane. In the co-pending application Ser. No. 09/563,612 filed May 2, 2000, a novel method and means is described for mounting a wind turbine on the upper end of a tower. Although the method and means described in the above-identified application represents a significant advance in the art, the instant invention is believed to be a further advance in the art.
A method and means for mounting a wind turbine on a vertically disposed tower is disclosed wherein the tower has upper and lower ends with the tower having a pair of guide rails positioned on opposite sides of the tower which extend between the upper and lower ends thereof. A turbine support, carriage or sled is provided which is adapted to have the wind turbine mounted thereon. The sled is initially removably supported on a self-propelled vehicle which has a winch mounted thereon which is preferably driven by the engine of the vehicle. The vehicle is initially positioned with respect to the tower so that the sled may be transferred from the vehicle to the lower end of the guide rails. In one embodiment of the invention, the vehicle is anchored to the ground or to a suitable foundation. The winch cable of the winch is then connected to a block and tackle assembly which is secured to the upper end of the tower and to the sled. The winch is then operated so that the sled is moved upwardly on the pair of guide rails. When the sled has been raised to a predetermined height with respect to the ground, a small crane positions the wind turbine on the sled at which time the rotor blades may be mounted on the wind turbine if the rotor blades have not been previously mounted thereon. The winch is then operated to raise the sled to the upper end of the tower. When the sled reaches the upper end of the tower, the wind turbine is slidably moved horizontally onto the upper end of the tower at which time the wind turbine is detached from the sled and is securely fastened to the upper end of the tower. The sled is then moved to the lower end of the tower and is removed from the guide rails and repositioned on the vehicle so that the sled may be used for the erection of other wind turbine assemblies. Prior to moving the vehicle to the next tower, the anchoring means is disconnected. In an alternate form of the invention, after the vehicle has maneuvered the sled into position to enable the sled to be transferred from the sled to the guide rails on the tower, the winch is disconnected from the sled and is anchored to the ground or to a suitable foundation. In yet another embodiment of the invention, the sled has an engine and a winch mounted thereon for movement therewith.
It is therefore a principal object of the invention to provide an improved method of erecting a wind turbine assembly.
A further object of the invention is to provide a method of positioning a wind turbine on the upper end of a wind turbine tower wherein the need of an extremely large crane is eliminated.
Still another object of the invention is to provide a wind turbine assembly wherein the wind turbine tower has a pair of guide rails positioned on opposite sides thereof to enable a sled to be vertically moved upwardly thereon with the sled supporting the wind turbine.
Still another object of the invention is to provide an improved method and means for mounting a wind turbine on a wind turbine tower which is less dangerous than the prior art methods of erecting the same.
Still another object of the invention is to provide a method and means for erecting a wind turbine assembly wherein a self-propelled vehicle is utilized which transports a sled from one tower location to another with the vehicle having a power means and a winch mounted thereon.
Still another object of the invention is to provide a sled of the type described above wherein the power means and winch remain on the sled as the sled is moved between the upper and lower ends of the tower.
Still another object of the invention is to provide a unique vehicle for transporting the wind turbine support sled from one tower location to another.
These and other objects will be apparent to those skilled in the art.